Process of separating metal plates.



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PROCESS 0F SEPARATING METAL PLATES.

APPLICATION FILED MAY Ia. 1914.

E 1,219,198. PaIenIeIIMar.13,191"/z f ILIMIIIIIIHl af/avg,... /3 Hwxc- BY @www @M ATTORNEY T sTaTns PATENT FT en- SAMUEL TROOD, OF NEW CASTLE, PENNSYLVANIA, ASSIGNOR TO INDUSTRIAL DEVELOPMENT COMPANY, A CORPORATION OF PENNSYLVANIA. i

PROCESS OF SEPARATING METAL PLATES.

Specification of Letters Patent.

Patented Mar. 13, 1917.

Application filed May 18, 1914. Serial No. 839,188.r

To all wwm t may concern:

Be it known that I, SAMUEL Tnoon, a citizen of the United States, and a resident of New Castle, in the county of Lawrence and State of Pennsylvania, have invented anew and useful Improvement in Processes of Separating Metal Plates, of whichthe following is a specification.

My invention relates to metal plates or sheets, and it has particular reference to means whereby piles or stacks of metal plates which have become somewhat cemented together or attached to each other in other ways can be quickly and conveniently separated without damaging the metal.

In order to illustrate the principles involved, the case of steel sheets such as are used in the manufacture of the so called tin plate will be considered although it willvbe understood that the method and devices which are applicable here may also be used with the proper modifications in many other cases where metal sheets requireseparation.

In the process of manufacturing steel vplate there is a step after the steelhas been rolled down to a certain thicknesskin which it is folded double upon itself several times and the entire pack afterward rolled thereby reducing the thickness of eachl sheet uniformly until the individual sheets have the required thickness. This is, of course, done while the pack is hot, and as a result of the combined heat, pressure and rolling, the sheets become firmly fastened together, partly due to the very intimate contact between the adjacent plates, and partlyto the fact that the small projections'and irregularities of the plates are so interlocked that it is necessary to stretch the metal in separating them.

In theA present process of manufacture, after the plates have been reduced in thickness as far as desired, they are-separated by a slow and expensive hand process, cleaned, pickled and placed in stacks for annealing. After annealing they are removed from the annealing ovens, cleaned, pickled and separated again rolled, usually cold, thus producing the finished plate ready for the application of tin.

From this description it will be evident that present commercial processes usually require the stacks of plates to be opened twice in the course of the manufacture of the sheets and that thehand process now in use is slow, expensive and introduces considerable scrap. The object of this invention is therefore to'providea simple, quick and inexpensive method of separating the plates. A further separate application, Serial No. 851,797, series of 1900, covers the machine and devices for accomplishing the result. In order to separate the sheets it is necessary to- First-break the cementing layer of slag which binds the sheets.

Second-to overcome the intimate contact between the plates. Y

Third-to stretch the interlocked parts sufficiently to eliminate such interlocking.

Referring to the drawings;

Figure 1 represents a section of two sheets before separation. y

Fig. 2 shows a section of two sheets when quickly bent.

Fig. 3 shows a section through two sheets and illustrates the sliding of one surface with respect vto the adjacent surfaces.

Fig. 4 shows in section two interlocking sheets. f e Fig. 5 shows anV end elevation of the rotary element.

Fig. 6 shows a side elevation of same element.

Fig. 7 is a side elevation of one form of machine for performing the process.

Fig. 8 is an end elevation ofthe same machine.

Reference to the drawings will make clear the principles upon .which my separation process is based. Fig. 1 represents a section `very much enlarged showing twoplates, 1

and 2, with the cement 3 between them in the condition which exists when they come from the rolls or from the annealing furnace for separation. It is of course understood that in most cases, vthere are many plates stacked one on top ofthe only two here are shown.

Fig. 2 shows what takes place when the plates with cement are subjected to iiexure of the proper magnitude and proper conditions. l indicates the cracks which are produced under these conditions in the cement.

Fig. 3 illustrates the conditions which cause a longitudinal shear between the surfaces of the sheets and the cement. This force, assisted by the weakening of the ceother although n ment by the fissures t of Fig. 2, tends to entirely separate the cement and the plates. The conditions shown in Fig. 3 due to the elongation of the side in tension and the contraction of the side in compression also tend to separate sheets which have projections somewhat interlocked as shown in Fig. 4.

ln this figure 5 Vrefers to projections on one sheet which have been rolled into the adja cent surface of the next sheet thus increas- Y ing the difficulty of separation.

ln all of the figuresfit is of course understood the space between the sheets which is partially filled with cement, slag, &c., has been very much exaggerated as well as the effects produced.

Y One'important property of the slag and cement which act to bind the plates together, is the elastic limit which, while considerably lower than steel, is still sufficiently high so that a considerable amount of slow bending may take place without causing separation. My experience has shown moreover that the cement and slag like glass and other silicates is stronger in compression than in tension, and may be cracked or broken by a quickly applied force such as a blow, although it may not be damaged by a similar force slowly applied.

It is well recognized that the time element has an important part in the deformation and rupture of materials, particularly the so-called brittle substances such as glass, scale, slag, porcelain, etc., in which the tensile strength is low. Extreme examples of these materials are pitch, tar,r paraffin, resin, etc., which will safely withstand without rupture a considerable force if gradually (that is, slowly) applierl, while the same force quickly applied in the form of a blow, or even a vibration, will rupture the material. There is evidently, therefore, a definite rate of application of force for cach material above which rupture occurs, and this rateis considerably higher for metal than for sabstances such as slag, scale, silicates, and the materials which bind the plates together. It therefore follows that there is a rate of application of force, or blows, such that the metal will merely be flexed and polished, while the bond between the sheets will be broken. For Vthese reasons, therefore, the speed of the impacts is a distinguishing fea:- ture, to'this process, and the method which forms the basis of this invention, is diferent from other previous methods in that, among other things, the speed of application of the blows is very high. Vhile the same effect as far as breaking the bond and therefore in separating the plates, could be obtained by a larger force less rapidly applied,

such a treatment l have founddeforms theV such a number that the process on this basis is not commercial. On the other hand theV rapid'blows of smaller force have only the'V flect of polishing and smoothing the sur! ace. 22

lt will be evident iffthe sheet is beaten with a rigid rotating hammer or projection that when the sheet projects into the path through which the hammers move it will be violently scraped and may be torni" It will also be clear that if one of the rigid hammers displaces that portion of the sheet with which it comes into contact the whole sheet will be moved so far away that many portions will not come into contact with the hammers.

In my device each khammer is mounted loosely upon the shaft, forced outward by centrifugal force, and if any one hammer strikes the sheet it yields slightly without necessarily scarring the sheet or forcing the pack back. ln other words, thel hammers are in effect resiliently mounted and behave as if supporte-:l 'upon springs.

There is therefore a decided difference bev tween the action of aI rigid hammer and a re siliently Vmounted hammer of the type here employed. This difference is most clearly seen if the sheets are considered to be absolutely rigid, which is in effect the actual condition of the majority of the packs of sheets of the kind to be treated.

lt also follows that many small resilient hammers will ract substantially independently and when applied with suiicient force produce substantially the same effect as the polishing sometimes known as planishing; Y.

and produces a metal similar to that known as Russia iron.

lt will be evident that as the beating rolls rotate successive series of the rings or hamnier elements will come into contact with the plates, thus delivering a series of blows, and as the hammer members are substantially alincd, the blows will be sul'istantially simultaneous= lf, however, the hammcrs are slightly staggered, the result is not seriously affected.V Since, however, the hammer members which deliver the blows are mounted independently of each other, the blows will be independent of each other in that any diminution of one or changein time of one blow due to the encountering of an obstacle or more or less resistance by onehammer, will not affect the other adjacent hammers which are delivering` simultaneous blows.

The blows of given series of hammers may therefore be described as a series of independent blows.

As previously pointed ont the'blows are given by loosely mounted hammers which have a considerable freedom of motion with n respect tothe shafts or members which support them. Thus if a hammer in motion encounters an obstacle which tends to retard its motion, the hammer may be moved relatively to the shaft which carries it, for a small distance, the extent of the freedom of motion depending of course upon the play or clearance between the hammer and its support. This amount of clearance therefore imposes the limits on the unrestrained motion of the hammer. It may be said, therefore, that within the limits thus imposed, the blow is unrestrained. The comparison is of course especially obvious when the effect of a rigid hammer is considered, and no degree of freedom whatever is allowed the hammer.

It will be obvious from this description that the blows which I employ may be dei' scribed as independent resilient blows, which are unrestrained within a given limit.

From this description it will be evident that my process is based upon the principle of delivering many blows with a resilient or yielding hammer, and the substantially independent action of the individual hammers allows the satisfactory treatment of an entire sheet.

To separate the sheets therefore, it is only necessary to create the conditions shown in Figs. 2 and 3 by forces quickly applied in a manner tending to place the cement or slag in tension, in other words to flex each portion of the surfaces to be separated, the bending to take place with a small radius of curvature. I have found modifications of the machine shown in Figs. 5, 6, 7 and S satisfactory to accomplish this result. The machine will be described in greater detail in said other application, however, as the present specification covers only the method employed.

In Figs. 7 and 8, 21 represents a substantial base on which is mounted a motor 22, to which is fastened pulley 23 which drives pulley 25 by means of belt 24. Rotating member 26 is driven by pulley 25, and supplies the blows which separate the sheets 19, which are mounted on bed plate 27 and guided by nprights 2S. The bed plate 27 may be raised or lowered by adjusting screws 30, which thus afford means for regulating the contact between rotating member 2G and the plates, thereby adjusting the blows as required.

In Figs. 5 and 6, 31, represents a shaft on which are mounted end plates (32) which carry rods 34 on which are loosely fitted the striking or hammer members 35.

In operation the motor 22 drives the rotating member 20 at the required speed. I have found three thousand revolutions per minute to give good results with a rotating member seven inches in diameter but do not wish to restrict myself to this combination of speed and diameter.

The rotor 26, having reached the proper speed the stack of plates 19, may be moved forward either by hand or by mechanical means until the rotor comes into contact with the forward edge of the lower plate, which is of course given an extremely rapid succession of sharp blows bythe loosely fitting hammer members 85 which are thrown radially outward by centrifugal force. As a result the lower sheets take a form somewhat similar to that shown in Figs. 2 and 8, but are straightened as the hammers pass to new portions of the plate. The sheets actually curl slightly from each other and on passing the pack entirely over the hammers the lower plate or plates will be completely loosened and fall Vaway from the pack. 3G shows a plate which has been loosened, being peeled from the pack by a projection 37 on the bed. Having separated one sheet the pack may be passed again over the hammers thus separating another sheet, and the process may be continued until all have been treated.

l/Vhen the pack 19 becomes light and the weight insuliicient to insure the necessary pressure between the hammers and the sheets, a new pack may be placed vupon the first one.

On consideration it will be evident that the rotation of element 26, which is equipped with a considerable number of hammers (eight per each transverse section) when rotated at a speed of 3000 revolutions per minute will give 1,440,000 blo-ws per minute to any portion of the plate, and each blow will have a force of many pounds. The result of the rapid succession of blows is to rapidly separate plates which are held together most tenaciously An additional result is to polish thoroughly the side of the plate exposed to the hammering action. This polish may be suflicient under some conditions to give a finish which is the equivalent of a rolling process, and may therefore materially improve the quality of the finished plate. It appears also, from tests which have been made, that the treatment by numerous rapid blows may act to render the texture of the iron finer, somewhat increasing its ductility and the ease and certainty with which tin may be applied to the plate.

It will be obvious that the results de- 115 scribed could be obtained by other means and other machines than those here illustrated. For example, a rapid pneumatic hammer, an electromagnetic vibrating hammer, or other mechanical equivalent of VtheV 120 device shown may be employed with satisfactory results, and these machines will be described and claimed in another application.

This specification therefore should not be 125 considered as confined to any specific machine for'accomplishing theresult, but is intended to cover the process which may be carried out by many different machines.

I-Iaving now fully described my inven- 130 tion, what I claim as new and desire to secure by Letters Patent, is as follows:-

l. The process of separating metal sheets, which consists in subjecting successive por* tions of the surface of said sheets to a series of simultaneous, independent, resilient blows.

2. The process of separating metal sheets, which consists in flexing successive portions of said sheets by a series of independent, resilient blows.

3. The process of separating a metal sheet which consists in the application to successive portions o the surface o' said sheet of a series of independent resilient sliding blows. Y

el. The process of separating a metal sheet which consists in ieXing and strtighteningportions of said sheets by the successive `applioation to said sheet of a series of simultaneous, independent, resilient, sliding` blows.

In testimony whereof, I have hereunto subscribed my naine this ninth day of May,

Copies of this patent may be obtained for :five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

